1. Field of the Invention (Technical Field)
The present invention relates to mirrors for optics applications and to methods for adjustment of same.
2. Description of Related Art
Historically it is difficult to provide an adjustable mirror that is both robustly mounted and that is relatively unaffected by dynamic loads. Typically the adjustment method becomes difficult to constrain and puts non-planar stresses in the mirror, distorting the reflective surface and degrading the image quality. Clamping forces applied after alignment tends to act along the adjustment vectors, causing misalignment and forcing iterations and use of “windage” during system alignment.
Mirrors are typically adjusted by displacing one edge of the mirror out of the mounting plane to generate a small tilt. This is accomplished by shimming or by incorporating a screw type adjustment device with a spherical washer mount.
Shimming is a trial and error method that can be time consuming and usually induces out of plane loads which distort the mirror surface. Screw type adjustments require additional precision hardware, add complexity, and are limited in resolution of adjustment to standard thread pitches. Both methods require operator expertise, take time, and tend to move when the final clamping load is applied.
Accordingly, mirrors are typically: (1) Difficult to adjust without cross talk into the other axis; (2) Susceptible to movement when clamping; (3) Susceptible to surface distortions when clamping; (4) Fairly complex, requiring multiple precision components; and (5) Requiring ample time to adjust and clamp during alignment.
The present invention provides a fine angular adjustment in one axis and allows a robust restraint system for the mirror, which is relatively insensitive to clamping and dynamic forces.